<h2>DESCRIPTION</h2>

<em>r.basins.fill</em>
generates a raster map layer depicting subbasins, based 
on input raster map layers for the coded stream network 
(where each channel segment has been "coded" with a unique category value) 
and for the ridges within a given watershed. 
The raster map layer depicting ridges should include 
the ridge which defines the perimeter of the watershed. 
The coded stream network can be generated 
as part of the 
<em><a href="r.watershed.html">r.watershed</a></em> program, 
but the map layer of ridges will need to be created by hand
(for example, through digitizing done in <em><a href="wxGUI.vdigit.html">wxGUI vector digitizer</a></em>).

<p>
The resulting output raster map layer will 
code the subbasins with category values matching 
those of the channel segments passing through them. 
A user-supplied number of passes through the data is 
made in an attempt to fill in these subbasins. 
If the resulting map layer from this program appears to 
have holes within a subbasin, the program should be 
rerun with a higher number of passes. 
<br><br>


<h2>NOTES</h2>

The current geographic region setting is ignored. 
Instead, the geographic region for the entire input stream's 
map layer is used. 

<h2>SEE ALSO</h2>

See Appendix A of the <b>GRASS</b> <a
href="https://grass.osgeo.org/gdp/raster/r.watershed.ps">Tutorial:
r.watershed</a> for further details on the combined use of
<em>r.basins.fill</em> and <em>r.watershed</em>.

<p>
<em>
  <a href="r.water.outlet.html">r.water.outlet</a>,
  <a href="r.watershed.html">r.watershed</a>,
  <a href="wxGUI.vdigit.html">wxGUI vector digitizer</a>
</em>

<h2>AUTHORS</h2>

Dale White, 
Dept. of Geography, 
Pennsylvania State University
<br>
Larry Band, Dept. of Geography, University of Toronto, Canada 

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